This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. In the last decade evidence emerged that a substantial portion of epigenetic information is transmitted in a form of chemical modifications of histones and associated DNA. Our research focuses on understanding the mechanistic basis by which covalent histone modifications regulate gene expression patterns during vertebrate development and differentiation. We are characterizing downstream effectors of histone methylation, or "readers", which recognize the methyl marks and translate them into specific biological outcomes. The proposed project focuses on identifying reader proteins that recognize Arginine 26 on Histone H3 (H3R26me). This modification occurs right next to the lysine 27 (H3K27), which is a critical residue for Polycomb mediated histone methylation. Moreover, we had recently shown that mutually exclusive H3K27ac versus H3K27me3 modification at enhancer elements in embryonic stem cells specifies their active versus poised state. Here we hypothesize that H3R26me may cross talk with modifications at H3K27 and to investigate H3R26me function we propose to identify and characterize H3R26me readers.